Lifting jack



FIG. 1 is a perspective view of the lifting jack according to the present design;

FIG. 2 is a right side view of the lifting jack;

FIG. 3 is a front view of the lifting jack;

FIG. 4 is a left side view of the lifting jack;

FIG. 5 is a rear view of the lifting jack;

FIG. 6 is a top view of the lifting jack; and,

FIG. 7 is a bottom view of the lifting jack.

The broken line showing of portions of the lifting jack is included for the purpose of illustrating environmental structure and forms no part of the claimed design. The lifting jack is shown with a symbolic break in its height represented by wavy lines to show that the lifting jack has no specific height. 

CLAIM The ornamental design for a lifting jack, as shown and described. 